Method of producing ore slurry

A method of producing an ore slurry that is used for recovering nickel and cobalt from nickel oxide ores by using a high temperature and pressure acid leach method utilizing sulfuric acid, the method comprising:

• pulverizing and classifying steps as well as an ore slurry condensing step,
• wherein the slurry condensing step uses as a flocculant solution a diluted solution of the flocculant that satisfies the following conditions of:
• (A) a flocculant molecular weight of 8×106 to 20×106 and
• (B) a flocculant dilution ratio of 0.1 to 0.5 g/L, and wherein with respect to the added amount of the flocculant, a flocculant solution having an amount corresponding to 50 to 150 g of the flocculant amount per ton of dried solid components in the ore slurry is added to the ore slurry so as to be made in contact therewith for a sufficient period of time, with the temperature of the slurry being set in a range from 35 to 45° C. upon transporting the slurry from the condensing step to the next process.